The artificial hip joint is one of the artificial joints inserted into the hip joint of a patient who is unable to use his or her hip joint due to breakage or wear of the hip joint, and it serves as a joint to enable the patent to maintain his or her usual way of activity.
The artificial hip joint consists of three major parts. That is, it is divided into: first, a first hemispherical acetabular cup provided with a liner on an inner circumferential surface, which is inserted into an acetabular portion of the pelvis and serving as a bearing for the femoral head between the femoral head and the acetabular cup; second, a stem inserted into the femoral head; and finally, a hemispherical head that replaces the femoral head.
Therefore, for patients with pain in the hip joint that is not functioning properly due to arthritis or dysplasia, trauma or infection sequelae, the part of the hip joint that suffers pain can be removed and the removed part can be replaced with the artificial hip joint mentioned above to thus restore the movement function of the joint and eliminate the pain.
Meanwhile, the artificial hip joint wears out as it is used for a long of time.
Particularly, the acetabular cup rubbing against the head has a high incidence of abrasion due to continuous use of the joint, and if the abrasion continues, in a severe case, osteolysis occurs around the acetabular bone with the acetabular cup inserted.
Therefore, it is necessary to remove the existing inserted acetabular cup from the acetabular bone and replace it with a new acetabular cup, and conventionally, in order to remove the acetabular cup from the acetabular bone, a separate tool having an annular cutting edge at a front end is brought into close contact with the inner surface of the acetabular cup, and the user manually rotates the tool to insert the cutting edge between the acetabular cup and the acetabular bone, and then lift up the tool on the cutting edge serving as a main axis to separate the acetabular cup from the acetabular bone.
However, the above-mentioned method has a shortcoming in that the acetabular bone is excessively cut and lost more than necessary in the process of detaching the acetabular cup, and the acetabular bone is directly exposed to the impact, thus having secondary damages.
In addition, it is also disadvantageous in that since the operator manipulates the tool directly, cutting is not uniform and it is also difficult to perform the operation with uniform force or range particularly when an inexperienced operator is performing the operation.